WSP07317

• File Number: 8210.140.20
• Description: Colorado River Basin Organizations and Entities - Colorado River Basin States Forum - California
• State: CA
• Basin: Western Slope
• Date: 1/1/1971
• Author: Myron B Holburt
• Title: Annual Report for the Calendar Year 1970
• Water Supply Pro - Doc Type: Annual Report

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WATER QUALITY

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Increasing salinity of the waters of the
Lower Colorado River Basin is one of the
major problems facing water users in the
Lower Basin. Historically, the river has had
a high content of dissolved minerals, and the
projected increase in future water use will
further increase salinity concentrations. This
will result in additional costs to agricultural
and urban users and cause other detrimental
effects. The Board is working with the Colo-
rado River water users, other California state
agencies, other basin states, and federal agen-
cies to develop programs to control the ri-
ver's salinity.

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Board'. Report on Colorado River Salinity

In August 1970, the Board completed its
report entitled "Need for Controlling Salin-
ity of the Colorado River." The report
showed that, since the early 1950's, there has
been a general rise in salinity of the Colorado
River. Average annual salinities were com-
puted, using the period 1963-67. At Parker
Dam the salinity averaged about 740 parts
per million (ppm) of total dissolved solids,
and at Imperial Dam the salinity averaged
about 850 ppm with substantially higher sea-
sonal values. If planned water projects are
constructed and if no salinity control meas-
ures are undertaken, average annual salinity
is projected to reach 1,1I0 ppm at Parker
Dam and 1,340 ppm at Imperial Dam by year
2000.
The report concluded that, although most
of the proposed developments affecting salin-
ity will occur in the Upper Colorado River
Basin, the Southern Nevada, Moapa, and
Dixie Projects as well as newly irrigataed
areas on Indian reservations planned for the
Lower Basin will cause increases in salinity
at Imperial Dam. The report also concluded
that, in the absence of salinity control meas-

ures, the annual damage in California alone,
due to increases in salinity, would be about
$40,000,000 by the year 2000.
A number of potential projects for the con-
trol of salinity were identified in the report
as having been studied on a preliminary basis
by the Federal Water Q!!ality Administra-
tion and the Bureau of Reclamation. If these
projects are found to be feasible and con-
structed, they would remove 2.8 million tons
of salt per year, or about 25 percent of the
11.4 million tons of salt per year estimated to
reach Hoover Dam by the year 2000. The
estimated cost of these projects is in the order
of $380,000,000, and the unit cost of salt re-
moval is in the range of $4 to $14 per ton of
salt per year except for one project at $32 per
ton. The report concluded that the salinity
problem is severe and that an action program
to control Colorado River salinity should be
developed which would include: (I) immedi-
ate commencement of feasibility studies of
salinity control projects that are sufficiently
well defined and have shown promise at the
reconnaissance level, (2) continuation of re-
connaissance level studies to identify other
potential salinity control measures, and (3)
development of financial and legislative pro-
grams that would provide for construction of
salinity control projects.

Salinity at International Boundary

The final year of operation under the five-
year agreement between the United States
and Mexico. embodied in Minute No. 218 of
the International Boundary and Water Com-
mission, was completed on November 15,
1970. Minute No. 218 provides that, at Mex-
ico's request, the highly saline pump-drain-
age discharge from the Wellton-Mohawk
Project in Arizona will be diverted around
Morelos Dam through a bypass channel con-

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